Development teams that shift testing left discover bugs earlier, enhance developer productivity, and increase release velocity by avoiding the long and costly delays that occur when bugs are discovered at the end of the development cycle. Shifting left creates faster feedback loops and allows for faster bug remediation. 

In order to understand a tester's value, we need to look at the role and understand the impact of the changing development process on this role.

In life and in test automation, a lot of things change as you mature—the challenges you face, the types of failures you experience, and the best ways to solve them. Let’s skip the “life lessons” and focus on the test automation angle here

TDD is a software development approach in which a test is written before writing the code. When TDD is properly set up, it can bring numerous advantages and become a cost-saver, providing true value to the business. When TDD is not properly set up or without understanding how it should be used, it can be a waste of time and money. Quality comes not from inspection but from the improvement of the production process